Klinische Wochenschrift
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Klinische Wochenschrift · Oct 1975
Comparative Study[The relationships between left ventricular volumes and ejection fraction in mitral and aortic regurgitation (author's transl)].
In 2 groups of patients with mitral valvular incompetence (MI, n equals 20) and aortic valvular incompetence (AI, n equals 22) intracardiac pressures as well as left ventricular volumes (enddiastolic volume, endsystolic volume, stroke volume, ejection fraction, regurgitant volume) were determined during routine left heart catheterization and left ventriculography. Data obtained were compared with a normal group (N, n equals 20). 1. Enddiastolic volume was increased by 32 per cent (MI) and 180 per cent (AI) respectively in comparison to normal. ⋯ The large contractility reserve in compensated AI may be referred to the altered contraction mechanism in aortic valvular regurgitation associated with i) decrese of isovolumic pressure development and increase of isotonic contraction, ii) increase of diastolic fibre stretch (preload) and iii) decrease of mean wall tension. Contractility reserve was essentially influenced by myocardial contractility. With decreases of contractility consecutively decreases of the total and the effective pump function of the left ventricle may occur despite unchanged contraction form and left ventricular dimensions.